I don't mind it happening, after all they are just assistants like you said, it's just the zero warning "I give up" that it seems to have. At least with Tesla's version it attempts to keep going while screaming at you to take over. The Toyota version just gives a small beep and by the time you figure out what the beep was it's given up completely and if you were unprepared (having your hands off the wheel[bad thing to do anyways, but a lot of people do it], only slightly following the road) you may be sliding into an adjacent lane.